Short-term effect of quercetin on the pharmacokinetics of fexofenadine, a substrate of P-glycoprotein, in healthy volunteers

Kyoung Ah Kim, Pil Whan Park, Ji Young Park

    Research output: Contribution to journalArticlepeer-review

    63 Citations (Scopus)


    Objective: The aim of the present study was to assess whether quercetin exhibited any inhibitory effect on P-glycoprotein (P-gp)-mediated drug disposition in humans using fexofenadine as a P-gp substrate. Methods: Twelve healthy subjects were enrolled in the study and treated daily for 7 days with 500 mg quercetin or placebo 3 times a day. On day 7, a single dose of 60 mg fexofenadine was administered orally. Plasma and urinary fexofenadine concentrations were measured, and pharmacokinetic differences between placebo and quercetin phases were assessed. Results: The mean plasma concentrations of fexofenadine were significantly increased after quercetin treatment compared to those of the placebo phase. The area under the time versus concentration curve (AUC) of plasma fexofenadine was increased by 55% by quercetin (2,005.3 versus 3,098.6 ng·h/mL, P<0.001) and similarly the maximum plasma concentration (Cmax) during the quercetin phase was elevated by 68% compared to that of the placebo phase (295.3 versus 480.3 ng/mL, P =0.006). Although the oral clearance of fexofenadine was decreased significantly by 37% after quercetin treatment (61.4 versus 38.7 L/h, P<0.001), no differences in the renal clearance and half-life were observed between placebo and quercetin phases. Conclusion: The results of the present study showed that short-term use of quercetin elevated the plasma concentrations of fexofenadine, probably by the inhibition of P-gp-mediated efflux in humans.

    Original languageEnglish
    Pages (from-to)609-614
    Number of pages6
    JournalEuropean Journal of Clinical Pharmacology
    Issue number6
    Publication statusPublished - 2009 Jun


    • Drug interaction
    • Fexofenadine
    • P-glycoprotein
    • Quercetin

    ASJC Scopus subject areas

    • Pharmacology
    • Pharmacology (medical)


    Dive into the research topics of 'Short-term effect of quercetin on the pharmacokinetics of fexofenadine, a substrate of P-glycoprotein, in healthy volunteers'. Together they form a unique fingerprint.

    Cite this